Plasmonic nanolasers, which are promising coherent light sources for integrated photonics, super‐resolution imaging, and ultrasensitive sensing applications, face the challenge of high thresholds due to inherent losses in plasmonic nanocavities. While considerable efforts have been made to improve the Q factor, typically quantified by the full width at half maximum (FWHM), intensity (ΔI) is another critical feature of plasmonic resonance. However, the combined influence of both the Q factor and resonance intensity of a plasmonic nanocavity on nanolasing threshold has not been sufficiently explored, as experimentally controlling one variable while keeping the other constant is challenging. Here, an ultra‐low threshold plasmonic nanolaser is demonstrated by systematically optimizing the plasmonic nanocavity. By carefully controlling both the FWHMs and resonance intensities of the plasmonic resonators, a record low threshold of 2.6 µJ cm−2 for a dye‐based nanolaser is achieved at room temperature– an order of magnitude lower than previous records. In addition, nanolasing under continuous‐wave (CW) excitation is reported at room temperature gained by the same dye molecule. The results provide new insights into the design of high‐performance plasmonic nanolasers and offer a promising path toward realizing applications of nanoscale coherent light sources.